Lifting jack



Jan. 18, 1927. 1,614,579

B.'w. TWYMAN LIFTING JACK Filed Sept. 17" 1925 10 6 I \4 M r INVENTOR. B.Wi0/sli/fe Twjman,

ATTORNEYJ- Patented den. 18, 12 27.

more rr tense 1B. WICKLIFFE TWYMAN, F COLUMBUS, 0H10'.

LIFTING anon.

Application filed September 17, 1925. Serial No. 56,315. I

- The object of my invention is to provide a lifting jack having a considerable range of movement yet of very low initial position, the construction being such that it can be produced at very low cost.

The accompanying drawings illustrate my invention.

Fig. 1 is a side elevation, in partial vertical section, of a jack embodying my invention;

Fig. 2 is an end elevation; Fig. 3 is a vertical section similar to Fig. 1 but with the parts extended;

Fig. 4 is a horizontal section on line of Fig. 1, and

Fig. 5 is a fragmentary perspective of a modification embodying a horizontally movable operating lever.

In the drawings B indicates a main body conveniently formed from a single piece of sheet metal comprising a middle base piece 10, the portions 11, 11 doubled over upon the base, and the vertical side pieces 12, 12 which side pieces form standards between which the lifting element is supported and moved.

One of the side pieces 12 is laterally. odset at 13 so as to receive a vertically movable stiffener plate 14 and the other side piece 12 is laterally, ofiset at 15 so as to receive a stiffener plate 16, said plates being retained in place by cross bars'17, 17 which are secured to and bridge the space between the upper ends of standards 12, 12 near one corner. Plate 16, along the edge distant 'from the cross bars 17, is flanged inwardly,

as indicated at 18 Fig. 4, and'in the space between the two stifiener plates 14 and 16,

A and between cross bars 17 and the flange 18 Lmount a vertically movable strut or lift- 5.1 member which is composed of two elements 19 and 20 articulated together by a n rule joint 21. The members 19 and 20 are conveniently formed of sheet metal into a U-shaped cross section as shown in Fig. 4,

and provided with ratchet teeth 22. Member 19 carries-a cross pin 23 which is pro jected laterally into vertical slots 24 and 25 formed respectively in the stiffener plates 14 and 16. I

Pivoted at 30, between standards 12, 12 is an operating lever 31 provided, at its'short end, with a pawl 32 adapted to engage teeth The lower end of strut element 20 is it cammed, as indicated at 36, so that, when it engages the. upraised portion 37 of base plate 10, it will be swung outwardly, during downward movement of the strut, as indi-, cated in Fig. 1.

The upper end of the strut element 19 is provided with a suitable saddle 40.

Cross bars 41 and 42 serve totie the standards 12 together, cross bar 41 being con- .veniently located so as'to limit the upward. movement of lever 31. A spring stop finger 43, held on cross bar 42, serves to gauge normal movement of lever 31 but permits abnormal movement suflicient to release the pawls.

In operation the saddle 40, in its lowest position, will lie closely adjacent the upper ends of standards 12, the lower end of strut 19 at that time being close to base 10 and the strut element 20 beingsubstantially horizontal. Cross pin 23 at this time lies in the lower parts of slots 24 and 25.

Reciprocation of lever 31 will cause pawl 1 32 to elevate the strut 1920 and, as the parts rise (being retained inelevated positions by pawl 34) cross pin 23 ultimately 61k gages the upper ends of slots 24 and 25 so as to carry the stifiener plates 14 and 16 upwardly, as shown in Fig. 3, thus stifl'ening the rule joint 21 laterally and also stidening the strut as awhole in its upwardly projected position.

In Fig. 5 the lever 310 corresponds to lever 31 shown in the other figures of the drawing and is provided-at its upper end with a pin 50 which lies in a slot 51 formed in a horizontally movable operating lever 52' pivoted on a vertical pin 53formed on the upper end of a plate .54 attached to the outer face of one of the standards12.

' In order to permit the return of the strut to its lowest position lever 31 is provided with a block 320 which, when the lever 31 is sufficiently depressed, comes into engagement with the pawl32 in such manner as to teeth, at which time pawl 32 will come into engagement with pawl 34 and also lift it out of the path of teeth 22, whereupon the weight, resting upon saddle 40, will-force the strut 19-20 to its lowest position and the lifted weight will drop. The jack is primarily designed for use inconnection with automobiles and, as these are rubbertired, a dropping of the lifted weight, as described above, is not injurious either tothe automobile or to'the jack.

I claim as my invention:

1. A lifting jack comprising a main body, a strut vertically movable in said main body and comprising two members articulated to-- gether upon a lateral articulation, a vertically movable stifiener member slidably associated with the strut and telescopically supportedin the main body, said strut and stiffener member having inter-engaging parts such that vertical movement of the strut will produce vertical movement of the stifi'ener member, and means by which said strut may be elevated relative to the main body.

2, Alifting jack comprising a main body, a strut movably mountedin said main body and comprising two members articulated together upon a lateral articulation, a stifi'ener element slidably mounted in the main body and telescoped upon the strut adjacent its articulation, a lost motion connection between the structure and stiflener element by which the stifiener element may be projected when the articulation moves beyond the 1 parallel sides, said sides being formed into vertical channels on their inner ia'ces, stiflve'ner plates slidably mounted in said channels, a strut slidably mounted between said stiffener plates and comprising two members articulated together upon a lateral articulation, a pin-and-slot connection between said strut and stiffener plates whereby said stiffener plates will bridge across the articulation, and means by which said strut may be p projected.

4. A lifting jack comprising a sheet metal body formed into a base and substantially parallel sides, said sides being formed into vertical channels on their inner faces, stiffener plates slidably mounted in said channels, a strut slidably mounted between said stiffener plates and comprising two members articulated together upon a lateral articulation and provided with ratchet teeth, a pinand-slot connection between said strut and stifiener plates whereby said stiffener-plates will bridge across the articulation, and means by which said strut may be projected,

said means comprising a pivoted lever and a pawl engaging the ratchet teeth.

In witness whereof, I, B. lVIoKLIFrn TWYMAN, have hereunto set my hand at Columbus, Ohio.

B. WIGKLIFFE TWYMAN. 

